PM
6/1/09
Block C


Big Idea

Many real world situations can be modeled and predicted using mathematics.

Essential Question: How can I use math symbols to describe a pattern?





Problem 4.2 and Follow Up

Karen wants to buy a stove from the Unlimited Store on an installment plane. The stove costs $305.

A. Write an equation you could solve to find the number of months it will take Karen to pay for the stove.

305=15x+30
-30+ 305= 15x+30-30
275=15x
275=15x
15 15
X=18.3 It will take her 18.3 months to pay for the stove.

B. Solve your equation using the symbolic method, how long will it take Karen to pay for the stove?

305=15x+30
-30+ 305= 15x+30-30
275=15x
275=15x
15 15
X=18.3 It will take her 18.3 months to pay for the stove.


Follow Up

1. In a-d use the symbolic method to solve the equation for x, check your answers.

a. 175=2.5x b. 64=19+3x
-2.5/175=2.5x/2.5 -19+64=19-19+3x
x

70 45

3x (45/3 and 3/3)
x=15


c. 15= 2x-50
-50+15=2x-50-50
-35=2x (-35/2 and 2/2)
-17.5

d. 60=-2x+14
-14+60=-2x+14-14
46=-2x (46/2x and -2x/2x)
X=23